Finding factors: 20 more difficult short investigations for KS2

The principle objective of this activity is to teach systematic thinking, in this case to test numbers chronologically with their factor partners up to the square root to ensure that there are no factors missing, and they are identified as quickly as possible.
It also provides opportunities to consolidate knowledge and understanding of times tables, square and prime numbers, mental strategies for calculating division, and the efficiency of using divisibility rules.
The sheets can be completed by hand or electronically on a PC or tablet.
The sheets can be used as homework, or as a time-filler to occupy more able children. It is also an exciting and popular task when used as a daily warm up in the form of a race. The race ends when a child finds the full solution, with merits for the winner and runners up.
With a robust group the pupil sheets can be abandoned and the task completed on individual white boards, so the children are not prompted with the correct format and number of factors.
When the number of factors is high you will find children calling time when they are a pair or two short, and having to go back to the drawing board; this all adds to the excitement.
The pack contains a set of twenty sheets at the higher level. Two packs at a less challenging level of difficulty are available either separately.
There is also a related scheme of work that can be purchased separately.